1. Field of the Invention
The present invention relates to a power connector and a contact retention structure used thereof, and more particularly to an assembly of a receptacle and a plug connectors for transmitting power between circuit boards and the mating receptacle and plug contacts used thereof.
2. Description of Related Art
Designers of electronic circuits generally are concerned with two basic circuit portions, the logic or signal portion and the power portion. In designing logic circuits, the designer usually does not have to take into account any changes in electrical properties, such as resistance of circuit components that are brought about by changes in conditions, such as temperature, because current flows in logic circuits are usually relatively low. However, power circuits can undergo changes in electrical properties because of the relatively high current flows. Consequently, connectors designed for use in power circuits must be capable of dissipating heat (generated primarily as a result of the Joule effect) so that changes in circuit characteristics as a result of changing current flow are minimized
U.S. Pat. No. 6,319,075 discloses a power connector assembly used in power transmission application, which includes a receptacle connector and a mating plug connector assembled on a circuit board, said receptacle connector includes an insulating receptacle housing and receptacle contact assembly assembled in said insulating receptacle housing, said plug connector includes an insulating plug housing and plug contact assembly assembled in said insulating plug housing. Referring to FIG. 1, each of said receptacle contact 10 includes two pieces of planar base portions 12, 14 connected on the top, and an upper and a lower curved contacting arms 16, 20 extending forwardly from the front of said base portion. When said receptacle connector is mated with said plug connector to be electrically connected, said plug and said receptacle contacting arms resiliently contact with each other, said receptacle contact 10 deforms under the pressing force when said plug contact being inserted, while the U shaped connection portion 42, 44 on top of said planar base portions 12, 14 of said receptacle contact 10 can provide an opposite supportive force to keep the contacting portion of said receptacle contact 10 from over deforming. Also, the receptacle as disclosed in this patent is configured in one piece, the connection portion of said base portion of the contact is U shaped, which needs to be bent after the base portion of the contact has been stamped, the process of bending normally results in a crack of the contact at a position where is bent, consequently the electrical conductive characteristics of the material could be influenced and the quality could be affected as well. Moreover, the high temperature during welding could also cause the relief of the inner metal stress of the bent contact, which could influence the precision of welding foot of the contact due to the expanding of the contact, as a result, the contact could not be smoothly contacted with circuit board and the welding foot of the contact could also be broken.
To overcome the disadvantages as disclosed in this patent, another Chinese Utility Model patent No. 200820031892.1 of the present applicant on an invention of a power connector assembly and mating contacts used thereof discloses an improved receptacle contact. Referring to FIG. 2, each of the receptacle contact pair 220 includes a pair of independent receptacle contacts 221, 222. Each of the receptacle contacts includes a rectangular planar base portion, a mounting leg extending downwardly from said base portion, and a contacting arm extending forwardly from said base portion. Said receptacle contact is configured in two pieces and manufactured directly by injection mould without the above problems as occurred during bending process, therefore the quality can be effectively improved while the cost of manufacturing can be reduced, also it can be easily assembled, and the manufacturing process becomes simple while the quality can be stabilized. In addition, because no connection or support is provided between said receptacle contacts 221, 222, the contacting arm of said receptacle contact could be over deformed or crumpled due to the pressing force exerted when the plug contact is inserted into the contacting arm of the receptacle contacts 221, 222, therefore the performance of power transmission of the receptacle contacts could be influenced.
Therefore, there are still some rooms that could be further improved about the configuration of the contact used in the power connector.